I also want to point out that Lana knows for sure that Lex hid a dead body for her so she really knows more than Chloe about certain things. A few words by an acquaintance (can't really buy the best friends schtick) is not really going to knock Lana off course. Chloe is not Lana's mama.

I think various advice columnists have told parents/friends/siblings that they can't get their children/friends/siblings to give up a relationship but have to let said person find out for themselves no matter how many reservations they have about the guy.